Gavin Brown’s Enterprise, of New York and Rome (with an Upstate New York gallery-restaurant with Rirkrit Tiravanija running through the summer), has among its offerings a new Arthur Jafa at back (the portraits are Miles Davis and Robert Johnson); a truly insane multiscreen Sturtevant, even by her high standards (The Dark Threat of Absence Fragmented and Sliced, 2002); and a handful of Alex Katz paintings. What a matchup!